Impact bit



Sept. 1, 1931. p H, @RANGER 1,821,212

IMPACT BIT Filed Sept, ll, 1928 INVENTOR. Pa/h. Gra/7 ef" ATTORNEYJ Patefed yse'pt. 1 1931, i

PATENT oFFlcE PAUL 1L entrena, or Los ANGELES, ALIFORNIA I MPAGT Brr applicati@ inea september 11, 192s. seria Na'eoalsao.v

This invention rel ates: .to a drilling tool. v`of the percussion type for earth boring, wherein thepercussive action -is obtained by rotation-of a drive stem in relation to the drill string. In` the rotary drilling of well holes of great depth, the hole drilled is seldom straight, due primarily to the slanting forma Ation and the encountering of boulders of various shapes in the formation which cause the drilling tool to be deflected laterally.

` cussion or standard drilling, the hammering acting in a vertical direction contributes to a relatively straight advance of the tool. The present invention contemplates a tool op'erable as to cutting action by percussion' and as to operation from the surface by rotation of the drive stem. x

It is a primary object of this invention to -20 provide a tool which has a bit reciprocable by rotation of the drive stem and rotatable from the drill string so as to progressively.

change the location ofthe impact of the cutting blades. Other objects of this invention 25 are to provide details of structure whereby'4 ,a durable, strong, simple,and efficient drill of thel character described is obtained, one which is economical to manufacture and easy to manipulate and operate.

These objects together with other: objects and corresponding accomplishments areobf tained by means of the embodiment of my invention illustrated in the accompanying drawings, in which Fig. 1 is a vertical section through a well y hole showing a core drill in section and partly in elevation; Fig. 2 is an elevational view partly in section on an enlarged scale showing the cam coupling between the drive stem and the-tool stem; and Fig. 3 is a sec.

tion as seen on the line 3&3A of Fig. l`

- Referring with more'particularity to the i drawings, a well hole 5 is shown and disposed therein in cutting osition is the bit.

' 45 Extending from4 the sur ace .is a string of drill pipe, a fragment of which is indicated by 6. Attached to the drill pipe in. any suita le manner is an adapter 'I having a threaded socket. toreceive the threadedend of a shell 8. The cage formed by the adapter' and shell houses a mechanism -for .changing rotary into: reciprocating motion. A closure plate 9 for the shell is provided at the lower end and has an opening at the center thereof for the passage of `the tool stem'. Adjacent its upper end is a guide 10 for the drive' stem. Intermediate the guide and the closure plate is a' thrust bearing plate 11.

. Extending through'the closure plate so as -to be' reciprocable therein is a hollovv7 tool stem 12 forming a core retainer andhaving attached thereto at the lower end a percussion corebit 13. Thisl bit may be of any suitable type, and is herein shown as having four blades there being a core mouth not shown. The upper portion of the. tool stem is externally square and extends through a corresponding square' opening in the thrust bearing 11, so as to be held against rotation in relation to the shell and to permit reciprocation. j Clamped to the. tool stem is a collar 14 serving as a seat for a compression spring 15, -the latter Abeing interposed between the bearing and the seat. Below the seat and resting upon the closure plate is a buffer advance'or project the tool stem and produces the impact or cutting stroke of the bit. The buifer spring is to prevent shock in the cam as will be later described. Secured to the upper end of the tool stem is a cam follower 17 in the form of a collar, -there being projections on its lower face extending axially of the tool stem. These projections have an inclined approach face 18 anda drop-off face 19. Extending through the drill pipe is a hollow drive stem, a fragment of which is indicated by 2O in Fig. 1. Itcarriesat its lower end a cam sleeve '21. .Secured 'to the cam sleeve is a cam plate 22 forming-in eifect a collar about the tool. stem. The c'am 22 'has projections 23 extending longitudinally of thev stems for coaction with the projections on the follower. Interposed between the bearing 11 and the cam 22 is a bearin washer`24. 'A core barrel liner 25 secured in t e tool stem `12is slidably received in drive stem 20 so as to provide a slip joint connected and to protect the core captured.

The compression spring maintains the follower in engagement with the cam. When the follower has its high dwells resting upon the projections 23, as shown in Fig. 2, the tool stem and its bit will be retracted. The compression spring at this time will have energy stored therein for advancing or projecting the bit upon its impact stroke. As the cam and follower rotate with respect to one another, the tool stem is retracted, the inclined faces 18 riding over the projections 23 until the bit is fully retracted. Further movement then causes the cam follower to drop 0H the projections 23, the compression spring expending its stored energy to cause a blow. In the operation of the device, the drive stem 20 may be rotated, and the drill pipe maintained relativelyl stationary, being preferably turned slowly so as to position the blades of the bit at different angular positions at each blow. Obviously, the drive stem may be maintained stationary and the drill pipe rotated. However, upon relative rotation of the drive stem and drill pi e, the bit is reciprocated to cause boring o the hole. It will be noted that there is suitable provision made for circulation. A

What I claim is 1.. A drill for well holes comprising a percussion .core bit, a rotatable operating headl including a tubular shell adapted to be connected to a drill pipe, a hollow tool vstem on said bit reciprocably mounted in said shell and held against rotation in relation thereto, a cam member on said tool stem, a thrust bearing in said shell, a hollow drive stem rotatably mounted in said shell having a slip jointconnection with said tool stem, a cam sleeve on said drive stem having a cam plate interposed between said bearing and said cam member, said cam member and cam plate having coacting projections extending axially of said stems with inclined approach faces and drop-off faces, and a spring tending to pro ject said tool stem and bit on its cutting stroke, said tool stem and drive stem forming a core barrel.

2. A drill for well holes comprising a percussion core bit, a rotatable operating head including a tubular shell adapted `to be connected to drill pipe, a hollow tool stem on said bit reciprocably mounted in said shell and held against rotation in relation thereto, a cam follower member on said tool stem having axially extending projections with inclined approach faces and drop-off faces, a thrust bearing in said shell, a hollow drive stem rotatabl mounted in said shell and having a slip joint connection with said tool stem, a cam sleeve on said drive stem nested over said cam follower member and provided with a cam plate interposed between said bearing and said follower member including projections extending axiall of said stem for coaction with the projectlons-on said follower member and a compression spring disposed between said bearing and said tool stem tending to project said tool stem and bit .onl 

